The study of the measurement and evaluation of coal-water-slurry stability

Coal-water-slurry (CWS) is a new type of substitute fuel for oil. It contains about 70% fine coal, 1% chemical additive, and water. It can be pumped, transported, atomized and burned. The main specific properties of CWS are as follows: fluidity, stability, thixotropy, atomizing and burning, etc. The stability and fluidity are the most important properties which are related to every phase of the CWS technology (manufacturing, transportation, storage, combustion). After evaluating the measuring methods for CWS stability used before, the authors designed and fabricated an oscillating-subsiding device and the corresponding electric testing circuit. According to the changing rate value of the oscillating device`s period, they can evaluate the CWS stability. They used four kinds of coal in the experiments, and studied the influences on CWS stability caused by the different coal, CWS concentration, CWS viscosity etc. They proved that it is correct to evaluate the CWS stability by using the device`s period changing rate, and it can quickly, accurately and quantitatively evaluate CWS character. This paper describes the authors` method of CWS stability evaluation.